Aronhold
# Siegfried Heinrich Aronhold

### Born: 16 July 1819 in Angerburg, Germany (now Wegorzewo, Poland)

Died: 13 March 1884 in Berlin, Germany

Show birthplace location

**Siegfried Aronhold** studied at the Gymnasium at Rastenburg (now Ketrzyn, Poland). After his father died his mother moved to Königsberg and Aronhold attended the Gymnasium there, graduating in 1841.

Aronhold then entered the University of Königsberg to study mathematics and natural sciences. There he was taught by Bessel, Jacobi, Hesse and Franz Neumann. Aronhold went with Jacobi to Berlin where he continued his studies under Dirichlet and Steiner. His doctorate from Königsberg was awarded in 1851.

From 1852 until 1854 Aronhold taught at the Artillery and Engineer's School at Berlin. He also taught at the Royal Academy of Architecture at Berlin from 1851. Aronhold was appointed professor at the Royal Academy of Architecture in 1863.

Aronhold took over Weierstrass's teaching at the Royal Academy of Arts and Crafts when Weierstrass became ill in 1862. Two years later Aronhold was appointed professor at the Royal Academy of Arts and Crafts.

Aronhold made important contributions to the theory of invariants. The topic was also being intensively studied by Sylvester, Cayley and Hesse but Aronhold was the first German to work on this topic. Certain linear partial differential equations which he came across in his work are characteristic of invariant theory and are named after him.

Earlier Aronhold had worked on plane curves and the problem of the nine points of inflection of the third order plane curve which had been discussed by Plücker some time before.

**References (2 books/articles)**

JOC/EFR December 1996